LCD display problem

Was having a problem with our Toshiba laptop, the screen would go black, but you could see a faint image in the background. Replaced the inverter and still had the same problem, then replace the lcd screen, and now the screen comes on very bright white but no image. Any ideas? I was thinking it is the video cable, is it supposed to click or anything when you put it back in, because this one just seems to go in, but doesn't seem secure. Thanks, Vickie